循环性情感症 是情感障碍之一、躁郁症的一种形式。在极性病谱中有定义此症。

具体而言，此疾患属于较轻微形式的第二型双极性疾患，伴随着时常在欢欣鼓舞与低落沮丧之间徘徊的情绪波动症状。一次轻躁期的发生便足以诊断为循环性情感症，不过大多数人也有轻郁期。如果有重躁、重郁或是同时重躁重郁时期三种之一的病史发生，则绝不该被判定为循环性情感症。循环性情感症的终生发生率为0.4-1％。男性和女性的比率相同，但女性更常寻求治疗。

Cyclothymia (/ˌsaɪkloʊˈθaɪmiə/), also called cyclothymic disorder, is a type of chronic mood disorder widely considered to be a more chronic but milder or subthreshold form of bipolar disorder. Cyclothymia is characterized by numerous mood swings, with periods of hypomanic symptoms that do not meet criteria for a manic episode, alternating with periods of mild or moderate symptoms of depression that do not meet criteria for a major depressive episode.